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Description: | Surveyor's pocket box sextant with leather case, made by John Dennett Potter, Poultry, City of London, London, England, 1855-1865. Consists of two circular lacquered brass plates with lid that acts as a handle when used. Fitted with Inlaid silver 134� scale (-5� to 160�) with 30' divisions and a silver vernier (1' div.). The index arm is rotated by a milled knob on the upper plate with two filter shades (red & green) operated by lever. The index glass is fixed with adjustment for the horizon glass. Fitted with magnifier (single lens) on hinged 40 mm swivel arm and choice of a large and a small pinhole sight but telescope missing. Marked �H O� the property mark of the Hydrographic Office of the British Admiralty. | License: | http://creativecommons.org/licenses/by-nc-sa/2.5/ | Subjects: | box sextant instrument case | Temporal: | 1855-1865 | Source: | Science Museum | Creator: | Potter, John Dennett | Identifier: | 1876-989 | Go to resource |
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